Stereochemistry of reductions catalyzed by methyl-epimerizing ketoreductase domains of polyketide synthases.

ABSTRACT: Ketoreductase (KR) domains from modular polyketide synthases (PKSs) catalyze the reduction of 2-methyl-3-ketoacyl acyl carrier protein (ACP) substrates and in certain cases epimerization of the 2-methyl group as well. The structural and mechanistic basis of epimerization is poorly understood, and only a small number of such KRs been studied. In this work, we studied three recombinant KR domains with putative epimerase activity: NysKR1 from module 1 of the nystatin PKS, whose stereospecificity can be predicted from both the protein sequence and the product structure; RifKR7 from module 7 of the rifamycin PKS, whose stereospecificity cannot be predicted from the protein sequence; and RifKR10 from module 10 of the rifamycin PKS, whose specificity is unclear from both the sequence and the stru

SUBMITTER: You YO 

PROVIDER: S-EPMC3699853 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature